Pneumatic starter for internal combustion engine

ABSTRACT

A starter arrangement for an engine includes a fluid actuated rotary vane motor which is adapted to engage an associated engine. The rotary motor has a plurality of blades or vanes with each of the blades being made from a fiber reinforced plastic material to reduce friction. A sleeve, in which the rotary motor is positioned, has on its inner surface a hard metallic coating to reduce friction. A relay valve member selectively provides a pressurized operating fluid to the rotary motor. The blade material and the sleeve inner surface coating cooperate to enable the vane motor, when it is actuated by the relay valve member, to rotate in the sleeve with a minimum of friction thereby obviating the need for a lubricating agent.

BACKGROUND OF THE INVENTION

This application is a continuation-in-part of patent application Ser.No. 031,399, filed on Mar. 27, 1987 and now abandoned, which in turn, isa continuation of patent application Ser. No. 781,216, filed on Sept.26, 1985 and now abandoned.

This invention generally pertains to starters. More specifically, thepresent invention relates to a pneumatic starter for an internalcombustion engine.

The invention is particularly applicable to an air starter designed fortruck applications. However, it should be recognized that the pneumaticstarter of the present invention may also be adapted for use in otheengine environments such as off-highway equipment, emergency generators,locomotives, dirt hauling equipment, compressors and the like.

When a compression ignition engine is started, its crankshaft must berotated at a speed sufficient to compress the air in the cylinder to apressure at which its temperature is sufficiently high to ignite thefuel injected into the cylinder. With the unavoidable leakage of someair past the piston rings, it is essential that the engine be turnedover at a high rate of speed and this requires a substantial poweroutput from the starter motor. A pneumatic motor or "air" motor isespecially adapted for such starter applications since the motor cangenerate a large amount of power in a small frame size and since thereis no reduction of its power output at either low temperatures or hightemperatures as there would be with battery operated electric starters.The pneumatic motor is operably connected to the engine in such a waythat the rotation of the motor causes it to engage and crank the engineuntil the engine becomes self-sustaining.

Such a pneumatic motor system includes a tank which contains a supply ofpressurized fluid used to rotate the pneumatic motor. Systems of thistype also commonly utilize a relay valve interposed between thepressurized tank and the pneumatic motor. This valve is normally closedand is selectively opened to feed pressurized fluid to the pneumaticmotor to actuate the latter.

In one known positive displacement pneumatic motor, the blades or vanesof the motor engage an eccentrically located inner surface of a sleevewhich provides a circumferential restraint but radial freedom ofmovement for the blades. The pneumatic motor is thus positioned withinthe sleeve in an eccentric manner so as to provide a number of chamberswith the sleeve. The vanes are thrust into intimate contact with thesleeve and a considerable amount of frictional heat is generated. Thereis thus a need to provide lubrication to the motor to prevent undue wearof the vanes. If such a lubricating means is not provided, or if thelubricating means should fail, the sleeve and the vanes would becomesubject to failure in a very short period of time due to friction.Generally speaking, such a lubricating means includes a mechanism forentraining a measured charge of atomized lubricant into the airdelivered to the starter at the beginning of each starting operation.

However, such lubricators are relatively expensive in relation to thecost of the entire air starter system, up to approximately one sixth ofthe cost of the whole air starter. Moreover, lubricators also add to themechanical complexity of the entire system. Also, even with a lubricatorsystem, a conventional air starter only has a lifetime of approximately10,000 cycles by the end of which the sleeve is usually scored andrusted, due to moisture in the ambient air, and the vanes are worn.

Additionally, both bus operators and the marine industry haveexperienced annoying and costly problems with conventional air startershaving lubrication systems. These problems emenate from frequentlubricator malfunctions which cause an "over lubrication" conditionresulting in surplus lubricant being sprayed into the enginecompartment. The lubricant is eventually dicharged into the atmosphere.In the case of diesel engine buses especially, lubricant discharged intothe atmosphere worsens air pollution in urban areas. Generally, suchlubricant fluid can be the diesel fuel used by the engine itself. Evenwhen the conventional air starter lubricators are not malfunctioning,approximately 1 cc of lubricant fluid is discharged into the atmosphereon each engine start.

It is evident that the use of unlubricated air starter motors would beof great environmental benefit. Additionally, by providing anunlubricated air starter, a considerable sum of money could be saved infuel costs per year, since the "saved" fuel would have been expended tolubricate a conventional air starter.

Accordingly, it has been considered desirable to develop a new andimproved pneumatic starter for an internal combustion engine which wouldovercome the foregoing difficulties and others while providing betterand more advantageous overall results.

BRIEF SUMMARY OF THE INVENTION

In accordance with the present invention, a new and improved starterarrangement for an engine is provided.

More particularly in accordance with the invention, the starterarrangement includes a fluid actuated rotary vane motor which is adaptedto engage an associated engine. The rotary motor has a plurality ofblades with each of the blades being made from a fiber reinforcedplastic material to reduce friction and wherein the blades have a wearsurface made of the same material. The rotary motor is positioned in ahousing including a sleeve which has on its inner surface a hardmetallic coating and a microfinish of less than 10 micro-inches R.M.S.to reduce friction. A relay valve means of the starter arrangementselectively provides a pressurized operating fluid to the rotary motor.When such operating fluid is provided, the blade material and the sleeveinner surface coating cooperate to enable the motor to rotate in thesleeve with a minimum of friction thereby obviating the need forlubricating system for the starter arrangement.

In accordance with another aspect of the invention, a starterarrangement for starting an internal combustion engine with compressedfluid is provided.

More particularly in accordance with this aspect of the invention, thearrangement includes a housing having a metallic sleeve and a fluidactuated rotary vane motor rotatably mounted in the sleeve. The motorhas a plurality of vanes or blades with each of the blades being madefrom a fiber reinforced plastic material to reduce friction, whereineach of the blades has a wear surface made of the same material. Also,the sleeve has on its inner surface a hard metallic coating to reducefriction so that as the blade slides against the sleeve, minimalfriction occurs. A source of pressurized fluid is provided for actuatingthe motor. The sleeve has a microfinish of less than ten micro-inchesR.M.S.

In accordance with still another aspect of the invention, a pneumaticstarter for an internal combustion engine is provided.

In accordance with this aspect of the invention, the starter includes aninner housing including a sleeve having on its inner surface a hardmetallic coating a reduce friction. The coating comprises a chromiumelectro-coating having a hardness which measures at least 70 on theRockwell C Scale. Also, the sleeve has a microfinish of less than 10micro-inches R.M.S. A fluid actuated rotary vane motor is rotatablymounted in the sleeve. The motor has a plurality of blades with each ofthe blades being made from a fiber reinforced plastic material to reducefriction as the blades rotate in the sleeve. The fiber is made from anaramid material and the blades have a wear surface made of the samefiber reinforced plastic material. A source of pressurized air isprovided for actuating the rotary motor. An eccentric cam is providedfor positively displacing the blades when the motor is actuated.

One advantage of the present invention is the provision of a newpneumatic starter motor which runs with less friction than previousstarters.

Another advantage of the invention is the provision of a starterarrangement which obviates the necessity for a separate lubricatingsystem for the arrangement due to the reduced amount of friction whichis generated as the starter motor operates because of the motor'simproved self-lubrication properties.

Still another advantage of the invention is that the reduction in theamount of friction generated as the starter motor operates enables theelimination of the conventional expensive lubricator system contained ina traditional air starter as well as its attendant piping system. Thisreduces the cost of the air starter by approximately one sixth.

Yet an another advantage of the present invention is the provision of alubrication-free air starter which eliminates a source of environmentalpolution in comparison to a conventional air starter have a lubricatorsystem which discharges approximately 1 cc of lubricant into theatmosphere per start of the engine.

Yet still another advantage of the present invention is its provision ofa lubrication-free air starter which can save a considerable amount ofmoney per year per engine in fuel. The saved fuel would have beenexpended to lubricate a conventional air starter.

An additional advantage of the present invention is its provision of anair starter having an average life which can be up to ten or more timesas long as that of conventional air starter due to its reduced frictioncharacteristics.

Still other benefits and advantages of the invention will becomeapparent to those skilled in the art upon a reading and understanding ofthe following detailed specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take physical form in certain parts and arrangementsof parts, preferred embodiments of which will be described in detail inthis specification and illustrated in the accompanying drawings whichform a part hereof, and wherein:

FIG. 1 is a schematic side elevational view of a starter arrangement andrelated components according to a first preferred embodiment of thepresent invention;

FIG. 2 is an enlarged perspective view, partially broken away, of thestarter arrangement of FIG. 1;

FIG. 3 is a reduced exploded perspective view of certain components ofthe starter arrangement of FIG. 2;

FIG. 4 is a schematic cross-sectional view of the starter arrangement ofFIG. 2;

FIG. 5 is a greatly enlarged view through a portion of the starterarrangement of FIG. 4; and,

FIG. 6 is a greatly enlarged view through a portion of a starterarrangement according to a second preferred embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, wherein the showings are for purposes ofillustrating the preferred embodiments of the invention only and not forpurposes of limiting same, FIG. 1 shows the subject new starterarrangement in a complete starter installation. While the starterarrangement is primarily designed for and will hereinafter be describedin connection with a diesel internal combustion engine for a truck, bus,boat, or the like it will be appreciated that the overall inventiveconcept involved could be adapted for other engine environments, such asemergency generators, locomotives, dirt hauling equipment, compressors,and the like and also for engines other than diesel engines.

More particularly, the starter installation includes an air tank 10which is connected by an air conduit 12 to a relay valve means 14. Amanually actuated valve control member 16, which is usually positionedin the cab of a truck or other vehicle (not illustrated), controls theactuation of the relay valve means 14 of an air motor.

With reference now also to FIG. 2, the valve means 14 is preferablypositioned within a housing 20. Also positioned within the housing 20 isa sleeve 22 and a sleeve adapter 24 which admits pressurized fluid fromthe valve means 14 into a sleeve interior 26. The sleeve 22 has a bodysection 28 which has on its interior surface a coating layer 30 as bestseen in FIG. 5.

In one preferred embodiment, the sleeve is made out of a metal such asgray iron and the sleeve coating is made of an "armoloy" material. Sucha material is a hard chromium electrocoating having a hardness whichmeasures at least 70 on the Rockwell C hardness scale. This coating issold by the Armoloy Corporation of 118 Simonds Avenue, Dekalb, Ill. Thecoating is effective in increasing wear resistance in sliding surfacecontacts and provides superior corrosion and erosion resistance. Thiscoating may be on the order of 0.0002 inches in thickness. It is evidentthat the thickness of layer 30 has been greatly magnified in FIG. 5 foreasier visibility.

Alternatively, a metallic ceramic coating may be used for the innersurface of the sleeve. This coating combines metallic particles, such asaluminum particles, encapsulated in a ceramic with a slurry bindersystem. This coating also provides a great resistance to corrosion,erosion and abrasion. The thickness of such a protective film coatingcan vary from 0.001 to 0.006 inches. Such coatings are available fromMetallic Ceramic Coatings, Inc., Front and Ford Streets, Bridgeport, Pa.Such a coating provides abrasion and corrosion resistance and aids inreducing friction between components.

Another such coating is a titanium nitride coating which is availablefrom the Star Cutter Company of Farmington Hills, Mich. This type ofcoating can be applied through a physical vapor deposition process andwill result in a coating thickness of 0.0001 to 0.0002 inches. Thecoating has a Rockwell C hardness of approximately 85. Such a coatingeffectively improves abrasion resistance and corrosion resistance.

Still another possible coating is an electroless nickel alloy. Suchcoatings may have a thickness of up to 0.001 inch if desired, althoughthicknesses as small as 0.0003 inches can also be used. An electrolessnickel alloy also provides low friction properties and a smooth surfacefinish. Such a nickel coating can be obtained from the ArmoloyCorporation of DeKalb, Ill. A nickel alloy coating of this type can beinfused with a polymer such as fluorocarbon to provide an inherentlubrication. Such a polymer infused nickel alloy coating is availablefrom General Magnaplate Corp., of Linden, N.J.

With reference now also to FIG. 3, positioned in the sleeve interior 26is a rotor 40 having at least one rotor vane or blade 42 thereon. In thepreferred embodiment, five such rotor blades 42 are provided but, ofcourse, any suitable number of blades can be used. Driving the rotorblades 42 is an eccentric cam 44 as may best be seen from FIG. 4. Theeccentric cam 44 prepositions the blades 42 into the air stream flowfrom the air tank through the relay valve means 14. This design isconsiderably more tolerant of contaminants and frost than most prior artdesigns and provides instant torque and starting reliability even underadverse weather conditions.

With reference now to FIG. 5, it can be seen that each blade has a bladebody 46 which is provided with a plurality of strand-like reinforcingelements 48. In one preferred embodiment, the reinforcing fiber is anaramid fiber, such as KEVLAR brand fiber sold by E. I. duPont de NemoursCorp. of Wilmington, Del., which also provides great flexural strengthas the blade rotates in the sleeve.

Other reinforcing fiber could, of course, also be used. Among thesefibers are glass fibers, boron fibers, and carbon fibers, i.e. graphitefibers. The fibers are preferably woven into a "cloth" which is thencoated with a resin binder. The resin coated "cloth" is set in ahumidity chamber. A plurality of superimposed layers of such cloth,depending on the thickbess desired for the blade, are then provided in asheet to a press. The press applies heat and pressure to the sheet tobind the several layers together. Thereafter, blades can be fabricatedfrom the sheet.

If the fibers are made of glass, the resin can be an epoxy. On the otherhand, if the fiber are aramid, the resin can be phenolic. Of course, thevarious layers of fibers in the blade can be oriented in differentdirections or in the same direction, as desired. One advantage of suchreinforced plastic blades is that they are friction resistant. Anotheradvantage is that they are not prone to rusting thereby increasing thelife cycle of the air starter.

In order to provide an airtight chamber, the sleeve 22 is provided oneach end with a respective end plate 50, 52 as shown in FIG. 3. Withreference again to FIG. 2, a gear element 54, which is driven by therotor 40 through a shaft 56, is positioned adjacent the second end plate52. A second gear 58 is driven by the first gear 54.

The second gear 58 is part of a drive means 60 for transmitting thepower of the vaned motor to an internal combustion engine having aflywheel ring gear 62 (see FIG. 1). Also positioned on the housing 20 isan integral muffler 64.

In the present invention it has been found that the use of a sleevecoating 30 reduces the coefficient of friction of the rotor blades 42 asthey rotate against the sleeve 22. Also, the rotor blades are made of asuitable fiber reinforced plastic material which further reducesfriction. Such friction has in the past been responsible for the wearand corrosion of the sleeve 22.

A conventional air starter has an average lifetime of approximately10,000 cycles. Depending on the frequency of the starts per day, such10,000 cycles can be accumulated in 3 to 8 years of use. At the end ofthis time, the sleeve of the starter may have rusted or scored so as tobe unusable and the blades generally have become worn despite the use ofa lubricating system which supplies lubricant for the sleeve and theblades.

In a test of an air starter constructed according to the presentinvention, however, the use of the "armoloy" material together witharamid fiber reinforced plastic blades, resulted in minimal wear to theblades over 10,000 cycles of the air starter despite the absence of alubricating system. It was found that blade wear was less than 0.010inches even without external lubrication. It was also found that therewas negligible wear on the sleeve. It is estimated that the constructionof an air starter from the materials listed above will increase the lifecycle of the air starter up to at least 14,000 cycles and perhaps to asmuch as 30,000 cycles. Besides a longer life cycle for the air starter,the elimination of an external lubrication system results in aconsiderable savings on the cost of the air starter and also results ina much simpler and mechanically less complex unit.

In the preferred embodiment, the blades are made of aramid fiberreinforced plastic which can have a coefficient of thermal expansion ofapproximately 35.3×10⁻⁶ inches/inch °C. linearly and approximately32.9×10⁻⁶ inches/inch °C. crosswise. In contrast, the sleeve, which ismade of cast iron can have a coefficient of thermal expansion of12.96×10⁻⁶ cm/cm °C.

With reference now to a second preferably embodiment of the invention,as illustrated in FIG. 6, the invention is there shown as having anotherconstruction. For ease of illustration and appreciation of thisalternative, like components are identified by like numerals with aprimed (') suffix and new components are identified by new numerals.

In this FIGURE, the interior surface of a sleeve body 28' has been givena very smooth surface. The surface was reduced from 40 micro-inches, asin the embodiment of FIG. 5, to approximately 8 to 10 micro-inches, andideally to 5 micro-inches R.M.S. in the embodiment of FIG. 6. Thisfinish is achieved by honing the sleeve interior surface using thefinest honing stone presently available. Previously, a rougher finishwas acceptable for the sleeve inner surface since lubrication wasprovided during each start of the air motor. Now a smoother sleeve innersurface finish is considered very desirable despite its additional cost.

Extensive testing has revealed that the surface finish of the inner wallof the sleeve is critical in determining the life expectancy of the airstarter. In this regard, while a surface finish of 40 micro-inches mightallow up to 15 to 20,000 cycles on the air starter of FIG. 5 beforefailure, a microfinish of approximately 8 micro-inches has given asignificantly longer life. More specifically, a test run on such an airstarter having such a sleeve microfinish has exceeded 125,000 cycleswithout failure of the blades. Eventually, a rotor shaft 56' of the airstarter failed due to metal fatigue. However, there was a minimum ofscoring or pitting on the sleeve surface and a minimum of wear on thevanes.

The inner surface of the sleeve body 28' can be provided with a coating80 which can be made of hard chromium electro-coating, such as armoloy,having a hardness which measures at least 70 on the Rockwell C hardnessscale. Hardness tests also indicate a measurement of from 1020 to 1100on the Vickers Diamond Pyramid Hardness Scale. This equals 70 to 72 onthe Rockwell C Scale. The armoloy material conforms to the existingsurface of a body including threads, flutes, scratches, etc. with detaildown to approximately 8 micro-inches R.M.S. Additionally, armoloy willnot affect a growth on the surface of the material more than 0.0002inches under normal circumstances thereby eliminating the need forundersized design calculations in most applications. The coating 80works its way into the surface of the sleeve material and adheres sopositively that it will not chip, peel, crack, or flake when subject tostandard ASTM bend tests over a radius equal to half the thickness ofthe material to which it is applied.

Roughness, the finely spaced surface texture irregularity resulting fromthe manufacturing process or the cutting action of tools or abrasivegrains, has in general a greater effect on performance than any othersurface quality. The control of roughness appears to be very importantin prolonging the life of the air starter.

If desired, a slot 82 in a hub in which a vane 42' reciprocates can alsobe coated with a suitable hard material coating 84 such as armoloy. Thismay be advantageous in preventing the pitting or scoring of the slot 82as well as in preserving the vane material from scratches or othersurface degredation. The coating material 84 may be the same as thecoating 80 on the inner surface of the sleeve or it may be another lowfriction coating material.

The subject invention thus provides an air starter arrangement whichproduces less friction as the blades rotate in a sleeve than doconventional systems. Therefore, the present arrangement enables theelimination of conventional lubrication systems which are used in airstarters thus resulting in a considerable cost and material savings onthe starter arrangement.

Through a judicious selection of coating materials and vane materials aswell as through the provision of a microfinish on the sleeve innersurface in the range of 8 to 10 micro-inches, a tenfold increase hasbeen achieved in the life expectancy of air starters for engines. Morespecifically, while a conventional air starter has a life expectancy ofapproximately 10,000 cycles by the end of which the sleeve is usuallyscored and rusted and the vanes are worn, an air starter according tothe present invention can have a life expectancy of more than 100,000cycles.

The invention has been described with reference to preferredembodiments. Obviously, modifications and alterations will occur toothers upon the reading and understanding of this specification. It isintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims or the equivalentsthereof.

Having thus described the invention, it is now claimed:
 1. A starterarrangement for an engine, comprising:a fluid actuated rotary vane motorwhich is adapted to engage an associated engine, said rotary motorhaving a hub and at least one blade which is slidably mounted in saidhub and is made from a fiber reinforced plastic material to reducefriction, and wherein said at least one blade has a wear surface made ofthe same material; a housing including a sleeve in which said rotarymotor is positioned, said sleeve having on its inner surface a hardmetallic coating to reduce friction, wherein said sleeve inner surfacecoating comprises a chromium .[.electrocating.]. .Iadd.electrocoating.Iaddend.having a hardness which measures at least 70 on the Rockwell Chardness scale and a microfinish of .[.less than.]. .Iadd.approximately.Iaddend.10 micro-inches R.M.S.; and, .[.a relay valve means forselectively providing a pressurized operating fluid to said rotarymotor, .]. wherein said blade material and said sleeve inner surfacecoating cooperate to enable said motor to rotate in said sleeve with aminimum of friction thereby obviating the need for a lubricating systemfor the starter arrangement.
 2. The arrangement of claim 1 wherein saidfiber reinforcing material for said at least one blade is selected fromthe group consisting of aramid fiber, glass fiber, boron fiber or carbonfiber.
 3. The arrangement of claim 1 further comprising:a source ofpressurized operating fluid; a conduit means for interconnecting saidsource of operating fluid and .[.said.]. .Iadd.a .Iaddend.valve means;and, a driving means for transmitting the rotation of said motor to theassociated engine and wherein said driving means includes a pinion gearwhich cooperates with a flywheel of the associated engine to rotate saidflywheel.
 4. The arrangement of claim 1 further comprising:a mufflerwhich is secured to said housing; and, an eccentric cam which urges saidat least one blade outwardly as said vane motor rotates.
 5. Thearrangement of claim 1 wherein said at least one blade comprises anaramid fiber reinforced resin material.
 6. The arrangement of claim 1wherein said at least one blade comprises a plurality of superimposedlayers of a reinforcing fiber cloth coated with a resin binder.
 7. Thearrangement of claim 1 further comprising a hard metallic coatingprovided on a portion of said hub adjacent said at least one blade toreduce friction between said hub and said at least one blade as said atleast one blade slides in said hub.
 8. The arrangement of claim 7wherein said hub hard metallic coating comprises a chromiumelectrocoating having a hardness which measures at least 70 on theRockwell C hardness scale.
 9. A starter arrangement for starting aninternal combustion engine with compressed fluid, comprising:a housingincluding a metallic sleeve wherein said sleeve has on its inner surfacea hard metallic coating which measures at least 70 on the Rockwell Chardness scale, said coating on said sleeve having a microfinish of.[.less than.]. .Iadd.approximately .Iaddend.10 micro-inches R.M.S.; afluid actuated rotary vane motor rotatably mounted in said sleeve, saidmotor having a plurality of blades with each of said blades being madefrom a plurality of layers of a resin-coated fiber cloth material toreduce friction wherein each of said blades has a wear surface made ofthe same material, and wherein as said blades slide against said sleevethere is minimal friction occurring thereby obviating the need for aseparate lubricating system for the starter arrangement.[.; and, asource of pressurized fluid for actuating said rotary motor.]..
 10. Thearrangement of claim 9 further comprising a motor housing in which saidsleeve and .[.said.]. .Iadd.a .Iaddend.relay valve are positioned. 11.The arrangement of claim 9 wherein said blade reinforcing materialcomprises an aramid fiber.
 12. The arrangement of claim 9 wherein saidsleeve inner surface coating comprises a chromium electrocoating havinga hardness which measures at least 70 on the Rockwell C hardness scale.13. The arrangement of claim 9 wherein said sleeve inner surface coatingcomprises metallic particles encapsulated in a ceramic material, and aslurry binder system.
 14. The arrangement of claim 9 wherein said sleeveinner surface coating comprises titanium nitride having a hardness onthe Rockwell C hardness scale of approximately
 85. 15. The arrangementof claim 9 wherein said sleeve inner surface coating comprises anelectroless nickel alloy.
 16. The arrangement of claim 15 wherein saidnickel alloy coating is infused with a polymer such as fluorocarbon. 17.An unlubricated, and hence environmentally desirable, pneumatic starterfor an internal combustion engine, comprising:an integral housingincluding a sleeve having on its inner surface a hard metallic coatingto reduce friction, said coating comprising a chromium electrocoatinghaving a hardness which measures at least 70 on the Rockwell C hardnessscale and wherein said coating on said sleeve has a microfinish of lessthan 10 micro-inches R.M.S.; a fluid actuated rotary vane motorrotatably mounted in said sleeve, said motor having a hub and aplurality of blades with each of said blades being made from an aramidfiber reinforced plastic material to reduce friction as said bladesrotate in said sleeve, wherein said blades have a wear surface made ofthe same fiber reinforced plastic material; a source of pressurized airfor actuating said rotary motor; and, an eccentric cam for positivelydisplacing said blades in relation to said hub when said motor isactuated, the rotation of said vane motor in said sleeve, causing aminimum of friction thereby obviating the need for a separatelubricating system.
 18. The starter of claim 17 wherein said hub has aplurality of slots, one for slidably mounting each of said plurality ofblades, and further comprising a hard metallic coating provided on asurface of said hub at each of said slots to reduce friction betweensaid hub and said blades as said blades slide in said hub.
 19. Thearrangement of claim 18 wherein said hub hard metallic coating comprisesa chromium electrocoating having a hardness which measures at least 70on the Rockwell C hardness scale. .Iadd.
 20. A starter arrangement for acompression ignition engine, comprising:an air actuated rotary vanestarter motor which is adapted to engage the compression ignitionengine, said rotary motor having a hub with a slot therein, wherein saidhub slot includes a hard metallic coating to reduce friction; a bladewhich is slidably mounted in said hub slot, said blade comprising afiber reinforced plastic material to reduce friction; and, a housingincluding a sleeve in which said hub and blade are positioned, saidsleeve having on its inner surface a hard metallic coating to reducefriction, wherein said sleeve comprises a ferrous material and whereinsaid hard metallic coating on said hub slot and on said sleeve innersurface is a material selected from the group consisting of chromium,nickel and titanium, wherein said blade material, hub slot coating andsleeve inner surface coating cooperate to enable said motor to rotatewith a minimum of friction thereby obviating the need for a lubricatingsystem for the starter arrangement. .Iaddend. .Iadd.21. The starterarrangement of claim 20 wherein said housing sleeve hard metalliccoating has a hardness which measures at least 70 on the Rockwell Chardness scale. .Iaddend. .Iadd.22. The starter arrangement of claim 21wherein said housing sleeve hard metallic coating has a microfinish ofless than 10 microinches RMS. .Iaddend. .Iadd.23. The starterarrangement of claim 20 wherein said hub slot hard metallic coating hasa hardness which measures at least 70 on the Rockwell C hardness scale..Iaddend. .Iadd.24. The starter arrangement of claim 23 wherein said hubslot hard metallic coating has a microfinish of less than 10 microinchesRMS. .Iaddend.